The invention relates to a damper in which a damper block is arranged on a pivotable rod or lever and a damper head cooperates with a piano wire and is connected to the damper block by complementary curved surfaces.
Dampers of this type are known (cf. German Patent Specification No: 3221 or German Gebrauchsmuster No: 73 11 598).
In this type of damper, the work of aligning the damper head or the damper elements fixed thereto in relation to the piano wire is substantially simplified in manufacture of pianos i.e. independently of whether the damper head is connected to the damper block permanently via a layer of adhesive or detachably by means of a connecting device. The damper heads can be aligned automatically in relation to the piano wire with simultaneous and relative displacement with respect to the related damper block owing to the complementary curved connecting surfaces between the damper head and the damper block, before the damper block and the damper head are fixed together.
In the manufacture of pianos, more particularly of those having certain requirements with regard to quality, it is not only important to align the damper heads automatically in relation to the wire so that they abut optimally with their felt blocks and rest fully on the related piano wires. It is also necessary to align the damper blocks arranged on the pivotable lever or on a rod in rows in relation to each other and parallel to common reference planes. If such an alignment process has to take into account both the workmanship and aesthetic requirements for a quality piano, then this alignment process is necessary in many cases and, with the known dampers, requires a large amount of skill and a considerable expenditure in terms of time and labour and involves high costs. Thus the fact that the damper blocks are limited by flat surfaces which are essentially at right angles to each other, apart from the curved connection surface for the damper head, plays an important part. The difficulty of alignment lies in the fact that the damper block can be out of alignment in its spatial arrangement in relation to the common reference plane of the row of damper blocks in various respects. With reference to the damper lever or to the damper rod, the damper block must be aligned longitudinally of the rod and cross-wise thereto. The damper block can be twisted or tilted however about its longitudinal axis or about the two axes running cross-wise thereto. With the large number of these damper blocks arranged in a row, alignment of the damper blocks is a difficult task. Thus it is quite clear that alignment of the damper blocks must take place inside the common row before the damper heads carrying the felt blocks or the like are aligned in relation to the piano strings and are connected to the damper blocks, since each subsequent correction in the position of the damper block would lead to a worsening of the optimum abutment of the felt blocks against the piano strings.